In the past, chaser sets have comprised multiple-series sets of light units, each having a cord with cord segments extending between light units. Each cord had a single wire within each segment, and each light unit had a pair of bulb leads engaging a pair of contact elements which were connected within the light unit to the ends of two of the adjoining wire segments. The light units in each series set were staggered relative to the light units in the other series sets making up the chaser set. The cords for the series sets plus an extra cord ("return cord") normally have been wound together in an arrangement wherein all of the cords at each light unit, except the cord which is directly connected to the light unit, bypass the light unit. The wound cords have their wires connected together at one end and are connected at their other end to a controller unit adapted to plug into a standard electrical wall outlet The controller unit has a switching assembly functioning to rapidly sequentially connect the series sets of light sets to the power supply.
A typical chaser set has had four series sets of lights, thus requiring that there be five parallel cords wound together. In such an arrangement, the bulbs do not have any particular directional orientation; and thus it is difficult to mount such a set around a window, for example, so that all of the bulbs along each side of the window project in the same direction. Furthermore, the wound-together wires extending between the lights detract from the overall appearance.